Isoxazolone couplers in color photography



United States Patent ISOXAZOLONE COUPLERS IN COLOR PHOTOGRAPHY John Mathers Woolley, Manchester, England, assiguor to Imperial Chemical Industries Limited, London, England, a corporation of Great Britain No Drawing. Application October 17, 1955 .Serial No; 541,097

Claims priority, application GreatBritain October 22, 1954 14 Claims. (Cl. 96--55) This invention relates to colour photographic, images and more particularly to a novel process for the production of colour photographic images by colour development in the presence of a colour coupler, to photographic developers and to photographic material containing such a coupler, and to photographic materials containing coloured'images of the kind obtainable from such a colour coupler.

It is known that when a reducible silver saltimage is developed with a primary aromatic amino developing agent in thepresence of certain isoxazolones containing a reactive methylene group, dyestuffs of the azamethine class are obtained. Dyestufls of this class in general have poor chemical stability and poor fastness to light.

'We have now found that by developing thereducible silver salt with a colour developer in the presence of certain derivatives of isoxazolone which .contain no reactive "methylene group in the isoxazolone ring and which have not hitherto been known for use as colour couplers, a completely difierentprocess of colour coupling occurs.

According to our invention we provide a process for the production of colour photographic images which comprises developing an exposed gelatino-silver halide emulsion layer with a colour photographic developer in the presence of a colour coupler f the formula:

wherein Z represents the atoms required to complete a vh-omocyclic, heterocyclic or polycyclic nucleus and R represents hydrogen or an acyl group.

The nucleus represented by Z may carry substituents for example halogeno, sulphonic acid, carboxylic acid, 'carboxylic ester or amide substituents. Z may represent .for example the atoms required to complete a benzene .nucleus, unsubstituted or substituted, that is to :say the compounds may be B-y-benzisoxazolones which may carry substituents on the l-, 4-, 5-, 6- or 7-positions. (The .system of numbering used in this specification for fi-y-benzisoxazolones is that given in the The Ring Index by Patterson and Capell published by Reinhold Publishing Corporation (1940) (No. 729).) As an example of a vheterocyclic (and polycyclic) nucleus there may be mentioned the quinoline nucleus.

The colour coupler used in the process of our invention may be used in the developing solution or it may be included in a light-sensitive layer of .a'multilayer photographic material or in a non-light sensitive layer ad- 2, jacent to a sensitive layer or separated therefrom by a water-permeable colloid layer. I

For the latter purpose an insoluble colour coupler may be used, or a soluble colour coupler enclosed in particles of water-insoluble, water-permeable material but ,it is preferred to use colour couplers which contain a substituent rendering them fast to diffusion, for example an alkyl chain of at least 5 carbon atoms and, if desired, a solubilising group.

The colour couplers used in the process of our'inyentionmay be made by the general processes known for use.in the synthesis of flzy-benzisoxazolones for example by reducing the appropriate .o-nitrocarboxylic acid ,or an ester thereof. (forexample o-nitrobenzoic acid, 3 -nitr.o.- phthalic acid, 3,-l'litI'O-6-ClllOITOPhthfillC acid, 2-nitro-4-sulphobenzoic .acid, .5 octadecyloxy-6-nitro-trimellitic acid, 3-nitror4rhydroxy quinoline-2-carboxylic acid, ethyl ester or 2-nitroterephthalic-acid) to the corresponding :hydroxylarninoscompound, ring closing, and if desired,.subsequentlyreplacing the hydrogen atom attached to the-nitrogen .atom,-,by anacyl radical, for example by heating .the compound with acetic anhydride, ethyl chloroform- ,ate-,..p-toluenesulphonyl chloride or phenylisocyanate.

Als.o,.if desired, substituentsqmaybeintroduced into the nucleus. represented by Z, or-substituents. in .the said nucleus maybemodified .by known reactions; For example when 3-n'itrophthalic acid is used as startingmaterial .the Amarboxy-fl-' -benzisoxazolcne formed a may itself Ibe usedas .a. colour coupler, or it may be.;converted to the'corresponding l-acetyl-, l-phenylcarbamyl, l-carbethoxy or 1 p toluenesulphonyl derivative by substitution on the nitrogen -.'a.tom, or the; carboxyl group in 4-C2lI'b0Xyfi-'y-bGHZlSOXaZOIOHE:.01 :rits ll-substituted derivatives may be modified for example by converting to the corresponding carboxylic acid chloride and reacting'this' with an alcoholsuch as octadecanol, or an amine such as octadecylamine or '1-amino2-(N-methyl- 'N-octadecylamino)=benzene-5-sulphonic acid.

The colour photographic developers which may be used in the present'invention include the mono-, diand tri-amino-aryl compounds. Among the monoamino developers there may be mentionedtaminwphenols and amino-cresols and their ,halogen .derivatives and amino .naphthols.

The ,developerspreferably used and givingthe best results in connection with thepresent .inventionare the aromatic 01'IhO-.:and para-diamineszsllch as para-.phenylene -.diamine. and its substitution products.

The .colour coupling which occurs in the process of our invention when an exposed .gelatino-s'ilyer halide emulsion is treated witha primary aromatic amino developing {agent in the presenceof one of the colourcouplers as herein- :befotedefined, proceeds by .a surprising and wholly-unexpected reaction in'which the isoxazolone ringgis split and an azo...dyes tuif,is formed in which the residue of the .oxidationproduct of the developing agent is attached to the nitrogen atom which previously formed the tl-nitrogen atom .of the isoxazolone, ring. Forexample when 1 phenylcarbamylt-carboxy-fl-v-benzi-soxazolone is used as the colour coupler, and p-.di ethylamino-aniline is used as developing agent, a dye'stuif is formed which has the following formula-z (iJOOH' It will be noted that the acyl substituent on the nitrogen atom in l-position of the indazolone ring is split off during colour development.

According to a further feature of our invention therefore we provide a colour photographic element which contains in at least one emulsion layer, a colour image comprising a dyestufi of the formula:

wherein Z has the significance indicated above and X represents the group of atoms which together with the group -NH forms a primary aromatic amine which is capable of developing exposed silver halide emulsions.

By selection of suitable colour couplers, especially with regard to the atoms represented by Z in the above formula of the colour couplers, and by selection of suitable developing agents, it will be apparent that dyestuff images can be obtained with a wide range of hue, and it will also be apparent that by suitably after-treating the residual colour coupler, left after colour development a colour correcting masking image can be formed, or by selecting colour couplers which are themselves coloured, the residual colour coupler left after colour development can itself be utilized as a colour correcting masking image.

The dyestufi images formed by the process of our invention are superior to the known azamethine images in ,their chemical stability and their fastness to light and the process of our invention provides a simple method of obtaining colour photographic images of good fastness properties by direct development of an exposed gelatinosilver halide emulsion with a colour photographic developer.

The invention is illustrated but not limited by the following examples in which the parts are by weight:

Example 1 A developer solution is made up according to the following formula:

Parts Sodium carbonate, anhydrous 16.2 N:N-diethyl-p-phenylene-diamine sulphate 0.75 Potassium bromide 0.25 Sodium sulphite anhydrous 0.25 fiw-Benzisoxazolone 0.5 Water 250 A photographic silver halide emulsion layer which has been exposed to light is developed in this solution at 20 C. In the exposed parts of the layer, the silver halide is converted to metallic silver and the yellow azo dyestuif 2-carboxy-4'-diethylaminoazobenzene (sodium salt) is produced. This yellow azo dyestufi has much better stability to light than the azamethine dyestuffs produced by previously known colour development processes.

In place of the 0.5 part of fiz' -benzisoxazolone used in the developer solution in the above example there may be used the same Weight of the N-acetyl derivative of this compound when the same dyestutf is produced, the acetyl groups being split oil in the colour forming reaction.

In place of the N:N-diethyl-p-phenylene-diamine sulphate used in the developer solution in the above example there may be used 4-amino-3-methyl-N:N-diethylaniline, 4-amino-3-ethoxy-N:N-diethylaniline or p-phenylene diamine.

Example 2 In place of the 0.5 part of firy-benzisoxazolone used in Example 1 there is used 0.5 part of 4-carboxy-flz'y-benzisoxazolone which may be prepared as follows:

31 parts of 3-nitro-phthalic acid are dissolved in 130 parts of water. The solution is added quickly to a solution of 100 parts of stannous chloride in 100 parts of 35% aqueous hydrochloric acid. Heat is evolved and a crystalline solid is formed. The mixture is cooled to 20 C. and the crystalline product is filtered ofi, washed first with 20% aqueous hydrochloric acid and then with water and dried. 4-carboxy-fi:'y-benzisoxazolone is obtained in the form of pale yellow needle-shaped crystals (melting point 190-192 C.). The yellow azo dyestuil formed in the exposed parts of the silver halide emulsion layer is the sodium salt of 2:3-dicarboxy-4'-diethylamino-azobenzene.

The same dyestuft is obtained when in place of the 0.5 part of 4-carboxy-fiw-benzisoxazolone there is used 0.5

- part of l--acetyl-4-carboxy-fi:'y-benzisoxazolone (melting point 212 C.) which may be made by heating 4-carboxyfizy-benzisoxazolone with acetic anhydride.

Example 3 In place of the 05 part of ,Bzy-benzisoxazolone used in Example 1, there is used 0.5 part of 6-carboxy-flz'y-benzisoxazolone which may be prepared as follows:

16 parts of 2-nitro-terephthalic acid is stirred with parts of water at 10 C. and 12 parts of zinc dust are added at such a rate that the temperature of the mixture does not rise above 15 C. When all the zinc dust has been added the mixture is stirred for a further 30 minutes at 15 C. and the mixture is then filtered. The residue is washed with 50 parts of water and sulphuric acid is added to the combined filtrates and washings until the mixture contains 10% free sulphuric acid. The solution so obtained in boiled and then cooled. 6-carboxy-fl:' -benzisoxazolone which crystallises out in filtered oif, washed with water and dried. The product is purified by stirring it with 20 parts of cold methanol for 15 minutes filtering off and recrystallising from methanol. The 6-carboxyflw-benzisoxazolone so formed does not melt below 300 C. The yellow azo dyestutf produced in the exposed parts of the photographic silver halide emulsion layer is 2:5-dicarboxy 4 diethylamino-azobenzene. The same dyestufi is obtained when in place of the 0.5 part of 6- carboxy-fl:y-benzisoxazolone there is used 0.5 part of l-acetyl 6 carboxy-fiz'y-benzisoxazolone (melting point C.) which may be made by heating 6-carboxy-flz'ybenzisoxazolone with acetic anhydride.

Example 4 In place of the 0.5 part of flzy-benzisoxazo1one used in Example 1 there is used 0.5 part of l-phenylcarbamyl- 4-carboxy-fiw-benzisoxazolone which may be made as follows:

1 part of 4-carboxy-fi:y-benzisoxazolone, 10 parts of dry dioxane and 1 part of phenylisocyanate are boiled together under a reflux condenser for 30 minutes. The mixture is cooled and the crystalline solid which separates from solution is filtered oil washed with methanol and ether and dried. The product melts at 190 C.

Example 5 In place of the 0.5 part of fiz'y-benzisoxazolone used in Example 1 there is used 0.5 part of l-carbethoxy-4-carboxy-flry-benzisoxazolone which may be prepared as follows:

1 part of 4-carboxy-fi:y-benzisoxazolone, 10 parts of chlorobenzene and 1 part of ethyl chloroformate are boiled together under a reflux condenser for 3 hours. The mixture is cooled and the crystals which separate from solution are filtered oil, washed with benzene and dried. The product melts at 156 C.

Example 6 In place of the 0.5 part of fiz'y-benzisoxazolone used in Example 1, there is used 0.5 part of l-p-toluene-sulphonyl-4-carboxy-{iz'y-benzisoxazolone which may be prepared as follows:

1 part of 4-carboxy-;8:'y-beuzisoxazolone is dissolved in 10 parts of pyridine and 2 parts of p-toluene-sulphonyl chloride are added. The mixture is heated to its boiling point and 10 parts of water are added. The mixture is emulsion.

-allowed to stand for minutes and-it isthen poured into ,a mixture of'lOO parts of-water and parts Ofhydrochloric acid.- The syrup which isprecipitated is separated and h'e'ated with 10 parts of methanol. The'clear solu- -=-'tion so formed is cooled when l-p-toluenesulphonyl-4-- :carboxy-,Bz'y-benzisoxazolone crystallises out.- The prod- '-'u'ct-is-filtered oil and dried.

It melts at 206 C.

Example 7 1 part of the octadecyl ester of -1-acetyl-4-carboxyphenylene diamine as developing agent. The developed silver is bleached and the silver salts-removed by'a' fixing *bath. A yellow azo dyestufi image-corresponding in v --gradation of density to the intensity of the-incident light is- -obtained. The octadecyl ester of 1-acetyl-4-carboxyfivy-benzisoxazolone may be prepared as follows:

- 2 parts of l-acetyl 4-carboxy-fiz'y-benzisoxazolone and i 10 parts of thionyl chloride are boiled under a reflux condenser for 2 hours. The excess thionyl chloride is distilled off and the carboxylic acid chloride dried in vacuo. A mixture of 1 part of thecarboxylic acid chloride so" formed, 2 parts of octadecanol and 10 parts of benzene are boiled under a reflux condenser for 2 hours. The mixture is cooled and the octadecyl ester of 4-carboxy-p:'y-'

benzisoxazolone which separates from solution, is filtered oif, washed with benzene and dried. It melts at 71-72 C."

' Example 8 ln place ofthe 1 part of'the octadecyl'ester used in Example 7 theremay be used 1- part of- 1=acetyl-1S:'y-

'benzisoxazolone-4-carboxyoctadecylamide=:which may be prepared as'follows:

1 *part' of 1-acetyl-,3:y-benzisoxazolonei carboxylic acid'chloride is dissolved in 10'parts of benzene and'the solution is added to a solution of 3.5 parts of octadecyl- ':amine in' 10' parts of pyridine and' 10 parts of benzene.

The solution is'boiled for 5 minutesand-thebenzene and excess pyridine are then removed by vacuum distillation. The residue is dissolved in 10 parts of methanol and the solution is poured into a mixture of 100 parts of water and 10 parts of hydrochloric acid. The white precipitate so formed is filtered olf, washed with water, then with methanol, and finally with ether and then dried. The product is recrystallised from methanol and then melts at 98l00 C.

Example: 9

lpart of 13:'y-benzisoxazolone-4-carboxy-(2'-N-methyl- N-octadecylamino-S-sulpho-benz)-amide is added to 5 -p'arts of methanol and 4 parts of water and 0.4% aqueous caustic soda solution is added drop-wise until a clear yellow solution is obtained. ThepH- of this solution is adjusted to 8.0 bythe addition of acetic acid or 0.4%

aqueous caustic soda solution, and the solution is'then added to 100 parts of a molten gelatino-silver halide The emulsion is coated as a layer on a substrate and the layer is dried. The layer is exposed to light, developed with 'a solution of NzN-diethyl-p-phenylenediamine, the developed silver is bleached and the silver salts fixed. The layer is washer with water. An

orange coloured azo dyestufi image is obtained.

The p:' -benzisoxazolone-4-carboxy-(2-N-methyl-N- octadecylamino-S-sulpho-benz)-amide used in this example may be prepared as follows:

2.2 parts of l-acetyl-fl:'y-benzisoxazolone-4-carboxylic acid chloride are dissolved in 18-parts of benzene and the solution is added to a-hot-solution of'.4.5 .parts of 1 amino 2(N methyl N octadecyl F amino). ben- 1 --zene-5-sulphonic acid in a-mixture of 10 parts ofbenzene and 8 parts ofpyridine. The solvent is removed 5 by vacuum distillation and the residue is dissolved in 20 parts of methanol. The solution is added to amixture it of 50 parts of ice and 20 parts of 35% hydrochloric acid. The gummy precipitate so-formedis allowed to settle, and the supernatant liquid is decanted. The gummyresidue is washed with water and thenboiled with parts of methanol. The solution so formed is cooledandthe 1 wpale grey solid whichis precipitated is filtered .ofhand recrystallised from glacialacetic acid. The product :melts at 212 C.

" Example 10 v1 In place ofthe 0.5 part of ,ezv-benzisoxazolone arsed inExample 1 there is used 0.5- part Of4C8I7bOXYe5-1Chl010- ,9 :"y-benzisoxazolonewhich may be prepared as -I-follows: 36 parts of 3 nitro=6 chlorophthalic' acid aretdissolved in""parts of water. The solution is'added quickly to a solution of l00 parts of stannous chloride in -1100 parts of 35%: aqueous "hydr'ochloricacidp Heat. is

*-evolved and-a'crystalline solid is formed; Theztrnixture is 'cooled to 20 C.- andthecrystalline product is filtered ofi' washed 'firstwith 20% aqueous hydrochloric .acid 4 and-then with -water and dried. 4-car boxy-5-chloro-'p: -benzisoxazolone is" obtained in the form of pale 'yellow =ne edle shaped 'crystals t melting point 178 C.)' J The yellovv dye'stuff formed in the expo'sed parts of theisilver halide emulsion layer is the sodiurn 'sa'lt of 2 :"3 dicarboxy- 4-chloro-4'-diethylamino-azobenzene.

J i Example 11 In place of the flv -benzisoxazolone used in the developing solution of Example'l there are used 5 parts of a 10% aqueous solution of [3: y-benzisoxazolone-6-sulphonic acid, when an azot dyestuff is formed which is bright yellow in colour in alkalinesolution and bright reddishmagenta in acid 'solution.

The'=10%' aqueous solution of pzv-benzisoxazolone-6- -sulphonicacid used in the above example may be:pre-

' pared as'follows:

-'2 nitrotoluene-4 sulphonic acid is loxidised in -the usual manner with alkaline permanganate solution to give 2- nitro-Lsulphobenzoic acid.

3 -2 parts of 2-nitro-4-sulphobenzoic acid are stirred in -'-'200 parts' of'water containing 16 parts of ammonium chloride, and 32 parts of zinc dust are'added gradually to the cooled mixture at such a rate-that the-temperature of the mixture does not rise above 30 C. The mixture is stirredfor 30 minutes at room temperature and'then filtered. "=The filtrate is strongly acidified with hydrochloric acid'andthen boiled to ring-close the Z-hydroxylamino-4-sulphobenzoic acid to form the benzisoxazolone- G-sulphonic acid. The solution so obtained is just neu- -'tralised withsodium carbonate and filtered. The benzisoxazolone-6-sulphonic acid-content ofthe filtrateis estimated by titration with N/-2 sodium 'nitrite-solution'and water is then added to the filtrate to adjust the concentration of 3:'y-benzisoxazolone-fi-sulphonic acid to 10% by weight.

Example 12 111 place of the fi:' -benzisoxazolone-used in the developing solution of Example 1, there is used 0.5 .part of'hydroxy-quinoline-isoaxazolone prepared as described below. A photographic silver halide emulsion layer which has been exposed to light is developed in the solution at 20 C. and. the silver and silver halide inthe exposed parts of the'layer are removed. The yelowishbrown azo dyestuff in the exposed parts of the layer is changed to a bright magenta colour on treatment .With Y hydrochloric acid.

. The hydro-quinoline-isoxazolone used in this example may be prepared as follows:

20 parts of 4-hydroxy-quinoline-2-carboxylic acid ethyl ester are dissolved in 18 parts of concentrated sulphuric acid below 30 C. 180 parts of a mixture of nitric acid and concentrated sulphuric acid (containing 10% of nitric acid) are gradually added to the solution and the mixture is stirred for 1 hour at 30 C. after the addition is complete. The solution is poured into 300 parts of ice and the yellow solid is filtered ofi and washed acid free. The filter cake is stirred into 60 parts of methanol, and the mixture is heated to the boil and filtered. The filter cake is washed with 60 parts of hot methanol and then recrystallised from 100 parts of acetic acid. 3- nitro-4-hydroxy-quinoline2-carboxylic ethyl ester is thus obtained in the form of small yellow crystals which melt at 286 C. 4 parts of this product are stirred in 60 parts of water containing 2 parts of ammonium chloride, and 4 parts of zinc dust are gradually added during 15 minutes, the temperature of the mixture being kept below 30 C. by the addition of ice as required. The mixture is stirred for a further 15 minutes and then filtered. Sufiicient hydrochloric acid is added to the filtrate until the mixture gives a strong blue colouration on Congo red paper. The turbid suspension so formed is boiled for 1 minute and then cooled and filtered and the mixture is stirred with 50 parts'of normal sodium hydroxide solution. 1 part of decolourising charcoal is added and the suspension is filtered. The filtrate, is acidified and the precipitate is filtered off and dried. The product has the following formula:

Example 13 In place of the 1 part of 8:y-benzisoxazolone-4-carboxy (2' N methyl N octadecylamino 5' sulphobenz)-arnide used in Example 9, 1 part of 4:6-dicarboxy- 7-octadecyloxy benzisoxazolone prepared as described below, is used. A yellow azo dyestufi image is obtained.

The 4:6-dicarboxy-7-octadecyloxybenzisoxazolone used in this example may be prepared as follows:

S-hydroxytrimellitic acid is converted to the trimethyl ester by heating it under a reflux condenser for 6 hours with methanol containing 5% by weight of-anhydrous hydrochloric acid.

parts of the trimethyl ester are dissolved in 100 parts of oleum (containing of free sulphur trioxide) at a temperature not higher than 30 C. The solution is stirred and cooled below 20 C. and 7.5 parts of potassium nitrate are added in portions at such a rate that the temperature does not rise above 20 C. When the addition of the nitrate is complete the solution is stirred for 30 minutes at C., and then poured onto 200 parts of ice. The gum which is precipitated is allowed to settle and the supernatant liquor is decanted. The gum is stirred with 35 parts of ether andmethanol is gradually added until the gum crystallises. The crystalline product is filtered ofl, washed with ether and dried. The S-hydroxy-6-nitrotrimellitic acid trirnethyl ester so formed is a white solid melting at 140 C.

10 parts of this nitro ester are stirred with 24 parts of octadecyl iodide and 4.8 parts of freshly prepared dry silver oxide at 100 C. for minutes. The precipitate of silver iodide is filtered oh and washed with ether and the filtrate and washings are heated to evaporate oil the ether. 40 parts of methanol are added to the residue left after removal of the ether and 30% aqueous sodium hydroxide is then gradually added until the mixture remains alkaline (pH greater than 10) after boiling for 5 minutes. 100 parts of water are then added and the alkaline solution so obtained is extracted with parts of ether, the aqueous layer is separated and again extracted with 100 parts of ether. The aqueous layer is separated and carefully neutralised by the addition of dilute hydrochloric acid. The buff coloured precipitate so formed is filtered oii, washed with 10% brine and dried. A mixture of S-octadecyloxy-G-nitro-trimellitic acid and its sodium salt is obtained as a light brown hard wax, of indefinite melting point.

10 parts of this wax, 50 parts of 35% hydrochloric acid, 20 parts of water and 10 parts of stannous chloride are boiled together under a reflux condenser for 30 minutes. The suspended oil initially present is replaced by a pale straw coloured flocculent precipitate. The suspension is cooled and filtered and the residue on the filter is washed with 15% hydrochloric acid, and then with water. The product is dried at room temperature and ground, to form a bufI' coloured solid. The product which appears to be the monsodium salt is used without further purification.

What I claim is:

1. Process for the production of colour photographic images which comprises developing an exposed gelatinorilver halide emulsion layer with a colour photographic developer containing a primary aromatic amine developing agent in the presence of a colour coupler of the formula:

wherein Z represents the atoms required to complete a nucleus selected from the class consisting of benzene and quinoline nuclei and R represents a member of the class consisting of hydrogen and an acyl group.

2. Process according to claim 1 wherein the colour coupler is present in the developing solution.

3. Process according to claim 1 wherein the colour coupler is present in the gelatino-silver halide emulsion layer.

4. A light sensitive gelatino-silver halide emulsion layer containing a colour coupler of the formula:

wherein Z represents the atoms required to complete a nucleus selected from the class consisting of benzene and quinoline nuclei and R represents a member of the class consisting of hydrogen and an acyl group.

5. A light sensitive gelatino-silver halide emulsion layer containing a colour coupler as defined in claim 4 which contains an alkyl chain of at least 5 carbon atoms and a solubilizing group selected from the class consisting of sulphonic and carboxylic acid groups.

6. A light sensitive, silver halide emulsion layer containing the octadecyl ester of 1-acetyl-4-carboxy-Bz ybenzisoxazolone.

7. A light sensitive, silver halide emulsion layer containing 1-acetyl-fl:v-benzisoxazolone-4-carboxyoctadecylamide.

8. The process of claim 1 wherein said color coupler is the octadecyl ester of 1-acetyl-4-carboxy-[3z'y-benzisoxazolone.

9. The process of claim 1 wherein said color coupler is 1-acetyl-B:'y-benzisoxazolone-4-carboxyoctadecylamide.

10. A light sensitive, silver halide emulsion layercon- 23546,:207 10 14. The process of claim 1 wherein said color coupler is a hydroxyquinoline-isoxazolone.

taining Bw-benzisoxazolone-4-carboxy-(2'-N-methyl-N- octadecylamino-5'-sulpho-benz)-amide.

11. A light sensitive, silver halide emulsion layer containing 4:6-dicarboxy-7-octadecyloxy benzisoxazolone. References Cited in the file of this Patent 12. The process of claim 1 wherein said color coupler 5 UNITED STATES PATENTS is p: -benzisoxazo1one-4-carboxy-(2-N-methyl-N-octade- 2 124 612 Eggert et a1 July 26 1938 t 2,331,326 Kendall et a1. Oct. 12, 1943 13. The process of claim 1 wherem said color coupler is 4:6-dicarboxy-7-octadecyloxy benzisoxazolone. 

1. PROCESS FOR THE PRODUCTION OF COLOUR PHOTOGRAPHIC IMAGES WHICH COMPRISES DEVELOPING AN EXPOSED GELATINOSILVER HALIDE EMULSION LAYER WITH A COLOUR PHOTOGRAPHIC DEVELOPER CONTAINING A PRIMARY AROMATIC MINE DEVELOPING AGENT IN THE PRESENCE OF A COLOUR COUPLER OF THE FORMULA: 